1. Field of the Invention
The invention concerns a process for making hand held and convenience snack food products comprising potato shreds. The process comprises formulating dough having a moisture content of about 55% to about 75%, preferably about 60% to about 72%, comprising potato shreds, cellulose gum, starch and other ingredients. The dough is extruded through a multiple extrusion nozzle, which in preferred embodiments comprises an outer extrusion segment and an inner extrusion segment which can be inserted into the outer extrusion segment to provide for extrusion of continuous ropes or casings having two or more axial cavities which are filled with savory fillings. If the continuous ropes are not of desired size and/or shape following extrusion, the continuous ropes may optionally be subjected to a roll over operation. The continuous ropes are cut and crimped to form uncooked cut casings. The uncooked cut casings are then cooked by baking, frying, par-baking or par-frying, combinations thereof or otherwise, and frozen to obtain the handheld convenience snack food product.
2. The Related Art
Hand held convenience snack foods having a filling surrounded by a casing typically have casings made from bakery formulas involving pastry dough. Bakery formulas generally involve grains and flours and the pastry dough tends to be homogenous which is both easy to form by extrusion or other means, or otherwise easy to fill. An example is cereal bar mixes made with pastry dough comprising multi-grains, and although these materials tend to have coarser grains compared to other pastry dough ingredients, the particles have substantial uniformity thus facilitating extrusion and filling.
Potato shreds are nonuniform and have bigger and longer particle size compared to grains and flours. As a result, dough comprising potato shreds lacks uniformity and is more difficult to handle and extrude. Dough comprising potato shreds will have the tendency to form open surfaces after extrusion or during the forming or filling process.
U.S. Pat. No. 4,888,192 concerns a method of extruding baked goods in the form of an extruded rope comprised of three materials. An outer expanded crispy layer and two non-dough filler materials are described as components. The dough is extruded under pressure and expands upon release from the nozzle surrounding a pair of tubes which place the filling into the center of the tubes. The filling material is supplied to the extruder through separate tubes and there is no discussion in the patent that the nozzle and/or extruder can be used to extrude dough comprising potato shreds.
U.S. Pat. No. 4,259,051 addresses extrusion apparatus for forming a hollow foodstuff of extruded plastic material which can be simultaneously filled. There is no discussion in the patent that the apparatus can be used for potato shred dough, and the apparatus cannot likely be used for extruding a plurality of axial cavities.
U.S. Pat. No. 5,527,179 describes an apparatus for extruding dough in hollow form through the use of a solid pin within the extrusion nozzle. U.S. Pat. No. 4,900,572 describes an apparatus for making dog food where an outer layer is extruded into a chamber having sleeves. An inner layer is extruded through the sleeves and, thus, the inner layer becomes covered by the outer layer. U.S. Pat. No. 5,645,872 describes extrusion of hollow shapes of material subject to coagulation by allowing gas or liquid to flow into the center cavity after extrusion to foster coagulation and avoid collapse of the hollow extruded shape.
U.S. Pat. No. 4,828,856 describes hash brown type potato products made from de-hydrated formed or fabricated potato shreds which can be re-hydrated and formed into patties said to simulate fresh cut potato products. The re-hydrated mass has a moisture content of 40% to 55% so that the product can be sheeted with a 1 to 2 millimeter opening between sheeting rolls. The potato dough made from the shreds described in this patent cannot be extruded because of needed high extrusion pressures which are said to rupture a significant portion of the potato cells. Non-critical ingredients for these products are carboxymethylcellulose, which is said to be a processing aid for the sheeting operation, and certain food gums to reduce fat or oil pickup (uptake) during frying. U.S. Pat. No. 5,492,704 describes a process for making potato strands comprising shreds for use in hash brown potatoes, and re-hydration of the shreds in the form of sheets to make a hash brown potato product is exemplified in the patent.
U.S. Pat. No. 5,891,596 describes potato mixtures shaped by extrusion or otherwise that are processed as a reduced fat flash frozen potato product. The formed potato shapes are made from blended potato pieces, and the blended product contains small pieces and, thus, not potato shreds. U.S. Pat. No. 3,399,062 describes dehydrated granular products, such as crushed dehydrated potatoes, containing some aggregates of individual cells, re-hydrated at low temperature in the presence of cellulose ether thermal gelling agent and extruded to obtain a french fried potato product.
U.S. Pat. No. 3,975,549 describes agglomerated dehydrated potato products made from dehydrated potato particles that, after re-hydration with a binder, are extruded to form french fries. The binder may be either a gum, such as guar gum, or free starch from modifying the potato solids. U.S. Pat. No. 3,987,210 describes an extruded french fried potato product comprising dehydrated potatoes in the form of flakes, granules, flour, diced pieces or mixtures thereof with a binder comprising more than about 25% amylose starch. The starch is said to retrograde when heated with water to form a film around the product and provide an oil barrier.
U.S. Pat. No. 3,486,673 describes extruded french fried potato products comprising dehydrated mashed potatoes, methyl cellulose and polygalacomannan gum, which are said to be essential ingredients. The combination of ingredients reportedly provide the product with an irregular external crust which permits the product to pick up a modest amount oil during frying. U.S. Pat. No. 5,242,699 addresses an application of a hydrocolloid coating to potato strips to provide an exterior crust when the strips are blanched or par-fried which may also retard oil adsorption into the potato strip. U.S. Pat. No. 5,620,727 concerns use of low molecular weight ionic hydrocolloid compositions to make film to reduce oil uptake. U.S. Pat. No. 3,687,688 concerns immersion of potato into a batter comprising sodium alginate for moisture control, and U.S. Pat. No. 4,900,573 concerns batter comprising hydroxypropyl methylcellulose which is said to function as an oil barrier.
Fat absorption/uptake of fried foods is one of the major concerns of consumers, particularly with respect to dietary concerns as fat provides approximately 9 calories. per gram to the food. Also, fat leaching from a prepared product during re-heating or reconstituting causes a greasy feel to food, and imparts undesirable organoleptic qualities to the food.
An object of the invention is a process that allows for the extrusion and processing of dough material comprising potato shreds to obtain an organoleptically acceptable and pleasing hand held convenience snack food, which can be easily reconstituted by the consumer, having a casing with axial cavities and savory fillings. These objects are achieved by the process and equipment described herein, particularly with regard to the moisture content of the dough material which enables extrusion without impairing the characteristics of the potato shred dough, the multiple extrusion nozzle and the cutting and crimping step of the process which isolates the savory filling material within the casing.
It is a further object of the invention to enable extrusion of a product having an outer casing with one or more axial indented ridge type connectors that allows sections of the casing to be broken apart so that the product can be consumed individually. A further object of the invention is the filling of the axial cavities simultaneously with extrusion. These, and other objectives of the invention, are achieved by the process and apparatus described herein.
Other objects of the invention are to make a hand held convenience snack food product that comprises a casing with potato shreds that can be extruded in the multiple extrusion nozzle and filled and then cooked, such as partially or fully fried or baked, without significant excess oil absorption during cooking and without oil or fat leaching during reconstitution and an extrudable casing comprising potato shreds that has structural integrity which can withstand the extrusion and filling process, and other processing to, in certain embodiments, axially join outer walls of two or more casings. These objectives are achieved by the unique potato shred matrix of the casing and the selection of cellulose gums which, with starch, forms a film on the exposed surfaces of the casing filling the voids in the potato shred matrix on exposed surfaces, which strengthens the matrix and inhibits oil/moisture transmission. These objectives are further achieved by the incorporation of axial indented ridge type connectors.
The process provides for an extruded baked or fried product comprising potato shreds wherein the integrity of the shreds is maintained despite the extrusion process. The cellulose gums and starch form a film around the exposed surfaces of the potato shred casing filling the voids at the exposed surfaces of the casing. As such, the casing maintains its shape during and after extrusion and the film helps control both oil pick-up during cooking and oil or fat leaching when the product is reconstituted. The moisture content is also important to processability as the moisture content of the casing, about 55% to about 75%, preferably about 60% to about 72%, regulates oil uptake during cooking in addition to facilitating extrusion.
In the present Specification, all parts and percentages are by weight/weight unless otherwise specified.
The process for making the snack food products comprises several steps. In general, the hand held and convenience snack products are formed from continuous ropes (referred to herein interchangeably as casings, ropes and continuous ropes), that are either hollow or solid. In the preferred embodiment, the casing is hollow and extruded through a multiple extrusion nozzle which provides for a casing having two or more inner walls, an outer wall and two or more axial cavities, such as two or three axial cavities defined by the inner walls, which. can be filled with a variety of savory fillings, such as meats, cheeses, or other processed dairy products, flavorings, spices, sauces and the like, or combinations of these. The casings are formed with axial indented ridge type connectors and can be radially cut to a lengthwise size to accommodate reconstitution, e.g., re-heating, in a conventional residential toaster or toaster oven. When the casing is cut, the casing is crimped to form ends of potato shred casing material which seals the filling within the axial cavities and the ends. In yet another embodiment of the invention, two or more ropes can be axially attached after extrusion. The details of the process and the various steps are discussed herein.
The casings comprise potato shreds which can be fresh cut or dehydrated, or a combination of fresh cut and dehydrated. The casing further comprises cellulose gum and starch, preferably modified starch, which form a film and fill voids in the potato shred matrix at the exposed surfaces of the casing, and serves to facilitate a stable potato shred matrix and provides a fat/moisture barrier for the casing material. Cellulose gums useful for the casing are microcrystalline cellulose, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose or combinations thereof. The matrix is critical to the mechanical properties of the product and, together with the moisture content of the extruded casing, allows for extrusion of the casing with sufficient structural support, particularly when the casing is extruded having one or more axial cavities so that the casing material will not generally collapse into the axial cavities. The film regulates moisture loss during frying to control fat uptake, and also retards fat from leaching from the product during reconstitution. The snack food product can be reconstituted by a number of means, including oven cooking, microwave cooking and heating in a conventional residential toaster or toaster oven. Leaching of fat during preparation would result in a greasy texture to the outer surface of the casing and poor organoleptic qualities. Thus, the matrix and film formed by the interaction of the gum and starch and potato shreds provide for an organoleptically acceptable product with a hash brown like texture and, particularly in the methods of toaster or toaster oven preparation, a product that will not undesirably leach oil or fat during re-heating or reconstitution.
The casing can comprise dehydrated potato shreds, fresh cut potato shreds or combinations thereof. When dehydrated potato shreds are used, the casing comprises about 20% to about 24% dehydrated potato shreds, about 3% to about 10% dried potato flakes, about 1% to about 4% starch, about 0.5% to about 2% flavorings, about 0.5% to about 2% sweetener, preferably dextrose, about 0.5% to about 2.5% cellulose gum and about 55% to about 75% water, preferably about 60% to about 72%. When fresh cut potato shreds are used, the casing comprises about 75% to about 95% fresh cut potato shreds, which may be moisture adjusted (e.g. dehydrated) to a moisture content of about 55% to about 75%, preferably about 60% to about 72%, about 3% to about 10% dried potato flakes, about 1% to about 4% starch, about 0.5% to about 2% flavorings, about 0.5% to about 2% sweetener, preferably dextrose, and about 0.5% to about 2.5% cellulose gum. Potato shreds as discussed herein are rectangular shaped potato pieces of random axial length, preferably up to about 76 millimeters, and a cross section of from about 6.4 millimeters to about 2.5 millimeters by about 3.2 millimeters to about 6.4 millimeters, preferably about 4.0 millimeters to about 2.5 millimeters by about 4.8 millimeters, and may be in dehydrated form.
The ingredients of the casing are mixed together and then the mixture is extruded through a multiple extrusion nozzle or a series of multiple extrusion nozzles to obtain one, or two or more cylindrically to elliptically shaped casings in the form of continuous ropes. In a preferred embodiment of the invention, the casing is extruded in hollow form, (i.e. tube like, having two or more axial cavities) and then filling is either co-extruded with the casing, injected into the axial cavities or stuffed into the axial cavities. The ropes are extruded through a multiple extrusion nozzle that provides for two or more axial cavities, preferably two or three axial cavities. Continuous ropes comprising a plurality of axial cavities can be extruded with axial intended ridge type connectors having radial widths of about 2 to about 12 millimeters formed at the outer surface of the casing material in the region between the axial cavities. The region between the axial cavities being the area of the extruded casing where the casing material is solid without the gap in casing material defined by an axial cavity.
The multiple extrusion nozzle comprises an outer extrusion segment and an inner extrusion segment which is inserted within the outer extrusion segment to enable extrusion of casing material with two or more axial cavities. Dough, preferably dough comprising potato shreds, is extruded through the annular space formed by the inside wall of the outer extrusion port of the outer extrusion segment and the outside wall of the inner extrusion port of the inner extrusion segment, thereby forming a potato shred casing having two or more axial cavities, such as two or three axial cavities. The savory filling materials are extruded, injected, or stuffed into the axial cavities through the inner extrusion segment. The multiple extrusion nozzle also forms a plurality of axial indented ridge type connectors by indentations in the outer extrusion segment. The multiple extrusion nozzle can also be used to extrude bakery dough comprising grain and/or flour.
If a snack food product comprising more axial cavities than are extruded in the casings is desired, a plurality of continuous ropes can be extruded on a conveyor. As the continuous ropes move on the conveyor, the continuous ropes physically move together, either through the movement of the conveyor or by physical means such as guides or wedges, and become connected at adjacent axial portions of outer walls of the casings to form a tube shaped snack food comprising two or more axially connected continuous ropes. By way of example and not limitation, casings each comprising two filled axial cavities can be attached lengthwise to form a set of attached casings comprising four axial cavities. An axial indented ridge type connector having a radial width of about 2 to about 12 millimeters is formed along adjacent outer walls of the axially connected continuous ropes. This axial indented ridge type connector is in addition to those formed within the continuous ropes during extrusion. The axial indented ridge type connectors provide the product with pull apart functionality, and adds rigidity to the casing of the overall product.
If the continuous ropes are not of a desired size or shape after extrusion, the continuous ropes may be subjected to a roll over operation which involves moving the continuous ropes under one or more rollers that compress the continuous ropes as desired. The ropes are cut radially to a desired length, to accommodate the method of preparation and size of equipment, (e.g. oven, microwave oven, toaster, etc.) for reconstitution, and the ropes are crimped at the time they are cut to form ends of potato shred casing material which seals the filling within the axial cavities and ends.
The cutting and crimping of the continuous ropes results in uncooked cut casings which are then cooked by frying or baking, including par-frying or par-baking and then frozen. The product can be reconstituted or reheated by means, such as a toaster, toaster oven or oven, or by microwave heating. The gum and starch provide a film around the casing which in part, inhibits the leaching of oil from the product during reconstitution thereby providing the product with acceptable organoleptic properties and texture, and reduced undesired greasy feel and, thus, the product has particular utility for hand held consumption. The gum and film also serves to enhance the structural support of the casing.
The process allows significant variation in product dimensions, particularly axial length, to accommodate differences in equipment sizes for re-heating and for future modifications by equipment manufacturers. The ability to vary the size of the product also allows for products to meet particular consumer choices. For example, the product can be cut to an axial length of about 8.5 centimeters to about 11 centimeters for current conventional toasters or toaster ovens, or could be cut longer for oven preparation or smaller to make a single serving pieces or hors d""oeuvres. The thickness is determined by some or all of the following: 1) the extrusion parameters, 2) the roll over operation and 3) the outer extrusion port of the multiple extrusion nozzle. The length is determined by cutting. The width is a function of 1) the size of the continuous ropes and 2) the number of continuous ropes axially attached together.